Typically, gas turbines are started by an auxiliary power source which may be an electric motor or a source of pressurized air. To start gas turbines based upon constant pressure combustion under the Brayton cycle, acceleration of the rotor to a rotational velocity is required by the auxiliary starter to a point where the net power output of the constant pressure combustor of the engine more than balances friction drag of the engine. In situations such as an Arctic environment, starting of turbines can be difficult because of the inefficiency of batteries used for powering the electric starter motor.
U.S. Pat. No. 3,439,495 discloses a self starting turbine which has a separate chamber which discharges pulses of combustion products through the main burner into a ring of nozzles to the turbine rotor blades or directly into the ring of nozzles to the turbine rotor blades. The pulses are used to accelerate the turbine rotor to a velocity sufficient to cause the compressor to provide gas at a sufficient pressure to make the main burner self sustaining to accelerate the turbine rotor up to operating speed. The turbine disclosed in the '495 patent utilizes the same ring of nozzles for impinging hot gases onto the turbine rotor which are produced by the pulse combustor and the main combustor. The flow through characteristics of the nozzles necessary to support efficient operation of the main burner do not maximize pressures achieved by the pulse combustor because of the relatively large cross-sectional area of the nozzles which impinge the gas combustion products onto the turbine rotor blades. The pulse combustor is not aspirated by air provided by the compressor.